Obturating device for the intake pipe of an internal combustion engine, especially for a rotary piston engine

ABSTRACT

The device includes a valve adapted to be closed, when the intake of fuel is reduced, to prevent the entry of burnt gases into the intake pipe. The valve is actuated by a mechanism arranged so that the valve can be fully opened and can shut the intake pipe at a short distance from the peripheral surface of the combustion chamber of the engine. The device is especially useful for rotary piston engines with peripheral ports.

United States Patent [1 1 Panhard Dec. 25, 1973 OBTURATING DEVICE FORTHE INTAKE [56] References Cited PIPE OF AN INTERNAL COMBUSTION UNITEDSTATES PATENTS ENGINE ESPECIALLY FOR A ROTARY 3,265,046 8/1966 Paschke123/8.l3 PISTON ENGINE 3,485,219 12/1969 Hamada.... l23/8.l3 3,587,5346/197l Weicheltm l23/8.l3 [75] memo Panhard Pans France 2,394,471 2/1946Paul 251/228 [73] Assignee: Societe De Constructions Mecaniques Panhard& Levassor Primary Examiner-Clarence R. Gordon Filed y 9 1971Att0rneyWaters, Roditi, Schwartz and Nissen [21] Appl. No.: 161,063 [57]ABSTRACT The device includes a valve adapted to be closed, [30] ForeignA li ti priority Data when the intake of fuel is reduced, to prevent theentry of burnt gases into the intake pipe. The valve is July 1970actuated by a mechanism arranged so that the valve can be fully openedand can shut the intake pipe at a g 123/8'01 g8 short distance from theperipheral surface of the com- [58] Fig. 90 24 bustion chamber of theengine. The device is espel23/90.25.188 S, 188 GC, 188 R, 1910; 251/228;418/61 cially useful for rotary piston engines with peripheral ports.

1 Claim, 2 Drawing Figures 1, OBTURATING DEVICE FOR THE INTAKE PIPE OFAN INTERNAL COMBUSTION ENGINE, ESPECIALLY FOR A ROTARY PISTON ENGINE Theinvention relates to an obturating device for the intake pipe of aninternal combustion engine, which engine, on one hand, is supplied withfuel through a supply device comprising means adapted to ensure suitablemetering of air and of fuel, under all operational conditions of theengine and, on the other hand, is provided with at least one intake portand one exhaust port of which the opening and closing are actuated bythe piston of the engine, the 'said intake and exhaust portscommunicating between themselves during a fraction of a cycle, thisobturating device comprising a valve adapted to be closed, when theintake of fuel is reduced, to prevent the entry of burnt gases into theintake pipe.

The invention relates more particularly, because it is in this case thatits applications seems to be most advantageous, but not exclusively,among these engines, to rotary piston engines with peripheral ports.

Of course, in engines of the above-specified type and especially inrotary piston engines, the intake and exhaust ports are placed incommunication, during a frac tion of a cycle, by reason of the geometryof the piston and of the engine. When the engine operates, a portion ofthe burnt gases not yet evacuated through the exhaust port is suckedtowards the intake pipe at the moment when communication is establishedbetween the intake and exhaust ports. In the cases where the supply offuel is reduced these burnt gases, which are introduced into the intakepipe and into the combustion chamber in the course of constitution, formwith the fresh gases, admitted in relatively small amount, an imperfectmixture of which the ignition is aleatory. Irregular or knockingoperation of the engine results there from. 1

It has already been proposed, to prevent the entry of burnt gases intothe intake pipe or, at least, to reduce the dead volume .into which theburnt gases can penetrate, to arrange, in the intake pipe, in thevicinity of the intake port, a valve adapted to be closed when the loadof the engine, that is to say the opening of the butterfly valve, issmall. Since the intake pipe assuming generally circular cross section,this valve has the shape of a disc and is mounted on an axis of rotationextending along the diameter of this disc. Under these condi-' tions,the said axis must occur sufficiently withdrawn from the intake portfor, on opening of the said valve, no portion of the latter becoming aprojection into the combustion chamber of theengine. In practice, theaxis of rotation of the disc must be separated from the peripheralsurface of the combustion chamber by a distance at least equal to theradius of this disc. As a result the burnt gases can occupy anon-negligeable volume of the intake pipe, comprised between the valvewhen it is closed and the intake port, of which the axial length is atleast equal to the radius of the valve.

it is a particular object of the invention to render the abovesaidobturating devices such that they respond to the various exigencies ofpractice better than hitherto and especially such that they no longerpresent, to the least degree, the drawbacks mentioned above of the priorart.

An obturating device of the type specified above, according to theinvention, is characterized by the fact that the valve is actuated by amechanism arranged so that the said valve, on one hand, can be fullyopened and oriented in a direction substantially parallel to the axis ofthe intake pipe at the level of the said valve and, on the other hand,can be oriented transversely to this axis to close the intake pipe at adistance from the peripheral surface of the combustion chamber of theengine along the said axis, less than one half of the dimension, of thevalve when the latter is fully opened, the assembly being such that thesaid valve does not project into the combustion chamber of the engine atany time, whether it is open or closed or in an intermediate position.

The actuating mechanism of the valve comprises:

on one hand a rod adapted to slide in a sleeve, inclined on theabovesaid axis towards the intake port, one end of the said rodprojecting into the said intake pipe, the middle portion of the saidvalve being articulated on this end, the other end of the rod beingconnected to a member actuating the longitudinal movements of the saidrods, preferably as a function of the load of the engine, I

and, on the other hand, a link of which one end is articulated on apivot mounted in the abovesaid sleeve, and on the other end of which isarticulated a portion of the valve situated, when the latter is opened,nearest the intake port.

Preferably, the pivot of the link is mounted in an elongated housing inthe direction of. the axis of the sleeve and is adapted to be moved inthe said housing in the course of the movements of opening and closingof the valve. 1

The invention consists, apart from the features mentioned above, ofcertain other features which are used preferably at the same time andwhich will be more explicitly considered below, with regard to apreferred embodiment of the invention which will now be described inmore detailed manner with reference to the accompanying drawing, butwhich is provided purely by way of illustrative example and in no waylimiting.

In the drawing FIG. 1 shows in cross-section, one embodiment of anobturating device constructed according to the invention, mounted on arotary piston engine, shown partially and FIG. 2 shows similarly to FIG.1, the obturating device in its closed position.

The drawing relates to the application of the invention to a rotarypiston engine of which the casing l and the rotary piston 2 have beenpartly shown.

The casing 1 is bounded internally by a cylindrical peripheral surface 3of which the cross-section hasthe shape of a two-lobed trochoid. Thepiston 2 has the shape of a prism with a curvilinear triangularcrosssection, of which the edges cooperate with the inner surface 3 ofthe casing l. The surface 3 constitutes the peripheral surface of thecombustion chamber of the engine. Lateral flanges (not shown), boundwith the surface 3 an inner space divided by the piston 2 into workingchambers such as the chamber 4.

The engine comprises at least one intake pipe 5 which passes through thecasing 1 and opens into the inside of the latter through an intake port6. A supply device such as a carburetter (not shown) is provided on thesaid pipe 1 upstream of the intake port 6 and supplies the engine withthe carburetted mixture.

The supply device comprises a main throttle member or butterfly valve(not shown) mounted in the pipe 5 and actuated by an accelerator.

The engine also comprises an exhaust pipe 7 passing through the casing 1and communicating with the inner space of the said casing through anexhaust port 8.

The opening and closing of the intake 6 and exhaust 8 ports are actuatedby the piston 2 of the engine. It is seen from the drawing, that in thecourse of its rotary movement, the piston 2 occupies, during a fractionof a cycle, positions such that the intake 6 and exhaust 8 portscommunicate between one another.

An obturating device 9 of the intake pipe 5 is provided to prevent, whenthe engine operates with the butterfly valve closed or slightly opened,that is to say at partial load, in deceleration or at slow speed, theentry of the burnt gases into said intake pipe 5.

The obturating device 9 comprises a valve 10 actuated by a mechanism 1 1arranged so that the said valve, on one hand, can be fully opened andoriented in a direction sustantially parallel to the axis of the intakepipe (see FIG. 1) and, on the other hand, can be oriented transverselyto the axis of the said pipe 5, at the level of the valve 10, to closethis pipe at an average distance d (see FIG. 2) from the peripheralsurface 3 of the combustion chamber of the engine, less than half 1(FIG. 1) of the dimension, along the said axis, of the valve 10 when thelatter is open.

In general, the intake pipe-5 has circular cross sectionsand the valve10 is constituted by a flat disc.

The actuating mechanism 11 comprises a cylindrical rod 12 adapted toslide in a sleeve 13. This rod is inclined to the abovesaid axis of theintake pipe and projects, in the direction of the intake port 6, intothe portion of the pipe 5 which passes through the casing l.

The rod 12 bears, at one end, a yoke 14 which projects, from the sleeve13, into the intake pipe 5. On this yoke 14 there is articulated a lug15 rigidly fixed to the middle portion of the valve 10.

The other end of the rod 12 comprises a housing 16 adapted to cooperatewith a flat element 17, with circular contour, in the form of pastille,borne by a member actuating the longitudinal movements of the rod 12 asa function of the load of the engine.

This actuating member is advantageously constituted by a finger 18adapted to turn with an axis 19 connected in rotation to the control ofthe butterfly valve. The finger I8 occupies the position shown in FIG. 1when the load on the engine is maximal or almost so, that is to say whenthe butterfly valve is fully open or almost so. A longitudinal slot 20is provided in the sleeve 13 to enable the passage of the finger 18, aswell as the angular movements of the latter.

The actuating mechanism 1 1 comprises also a link 21 of which one end isarticulated on a pivot 22 mounted in the sleeve 13, at the end of theportion of the latter which projects into the pipe 5. On'the other endof the link 21 is articulated the portion of the valve 10 situated, whenthe latter is open, closest to the intake port 6. More exactly, thisportion of the valve bears a lug 23, perpendicular to the plane of thevalve, hinged on the link 21.

The pivot 22 is mounted in a housing 24 elongated in the direction ofthe axis of .the sleeve 13. This housing 24 is constituted by the spacecomprised between, on one hand, a foot 25 extending the end of thesleeve 13 and provided with a lip extending radially towards the axis ofthe said sleeve 13 and, on the other hand, a zone of the outer surfaceof the rod 12 situated facing the said foot 25. The lip of the foot 25prevents the pivot 22 from emerging from the housing 24, longitudinally,towards the intake port 6. However, the said pivot 22 can be movedbetween the two longitudinal extremities of the housing 24.

Elastic return means (not shown) can be provided, which act on the pivot22 and tend to space it from the intake port 6.

It will be noted that a flat annular seat 26 for the valve 10 (FIG. 1)is provided in the intake pipe 5 slightly withdrawn from the innerperipheral surface 3. The average distance between the plane of the seat26 and the said inner surface 23 is precisely equal to d (FIG. 2). Tofix ideas, it may be stated that d is of the order of severalmillimeters, three or four for example.

When the carburetter mounted on'the intake pipe 5 is a dual carburetterwith one intake pipe (not shown) for the supply at slow speed and atpartial load, and a second intake pipe, corresponding to the pipe 5shown, for the supply at full load, the valve 10 is arranged in thesecond pipe and is adapted to close it completely when the engineoperates'at slow speed or at partial load or in deceleration.

When the carburetter, mounted on the intake pipe 5, is a singlecarburetter, the valve 10 is designed to enable, when it is closed, thesupply when the butterfly valve is partly opened, 'for example at slowspeed or at partial load. v

This being the case, the operation of the obturating device according tothe invention is as follows.

There will first be considered the case where the valve 10 passes fromits open position, shown in FIG.

1, to its closed position shown in FIG. 2.

This case corresponds, for example, to that of deceleration by releasingthe accelerator control, the butterfly valve (not shown) previouslyopen, is closed and the engine is caused to pass from full load to veryslight or nul load.

The release of the accelerator control causes the rotation of the finger18 in anticlockwise direction. The element 17 pushes the rod 12 from theleft to the right of FIG. I. By reason of the friction or, when theelastic return means are provided to act on the pivot 22, by reason ofthese eleastic means, the said pivot 22 is held in the portion of thehousing 24 most spaced from the intake port 6. Under these conditions,the lug 23 will describe an arc of a circle centered on the pivot 22 andof which the radius is equal to the length of the link 21. At the sametime, the yoke 14, which is moved longitudinally with the rod 12,actuates in its movement of translation the axle on which the lug 15 isarticulated. The latter has therefore a combined movement of translationdue to the movement of the rod 12 and a movement of rotation due to theaction of the link 21 on the lug 23. As a result, for the valve 10,there is a tilting movement, around the axle bearing the lug 15, inanticlockwise direction.

The assembly is arranged so that, when the valve 10 has turned throughan angle substantially equal to and is oriented transversely to the axisof the pipe 5, the tilting of the said valve in anticlockwise directionis prevented either by cooperation of the yoke 14 and of a portion ofthe valve, or by cooperation of the portion of the valve 10,diametricallyopposite to the lug 23,

'5 and the portion of the seat 26 situated nearest the exhaust pipe 7.

Under these conditions, supplementary movement of the rod 12 towards theintake port 6 causes, on one hand, a longitudinal movement of the pivot22, in the housing 24, towards the intake port 6 and, on the other hand,the full application of the valve 10 against the seat 26 and the closingof the intake port 6. This final phase of the movement can be atranslation of the valve 10 along a direction parallel to the axis ofthe sleeve, in which case the whole periphery of the said valve 10 isapplied simultaneously on the seat 26. This translation can be obtainedwhen the said valve 10 is prevented from turning in anticlockwisedirection by cooperation of the lug 15 (or of the middle portion of thesaid valve) with the yoke 14.

It is absolutely essential to note that in the course of its closingmovement, neither the valve 10 nor any of its parts project at any timeinto the working chamber It must be noted also that the dead space ofthe intake pipe into which the burnt gases can be introduced isextremely reduced, when the valve is closed, by reason of the smallvalue of the distance d.

From the beginning of closing of the valve 10, that is to say as soon asthe engine no longer operates at full load, efficient throttling of theintake pipe 5 is obtained since the initial phase of the movement of thevalve comprises the rotary movement of the latter in anticlockwisedirection around the axle bearing the lug l5.

Passage of the valve 10 from its closed position (FIG. 2) to its openposition (FIG. 1) is immediately apparent from the previously givenexplanations.

When full opening of the butterfly valve (not shown) is actuated so thatthe engine passes from partial load to full load, finger 18, from theposition that it occupies in FIG. 2, will turn in clockwise directionand will displace the rod 12 from the right to left of FIG. 2.

Pivot 22 no longer being in abutment against the bottom of the housing24, the displacement of the yoke 14 and of the lug 15 from the right toleft FIG. 2 will cause, especially if said pivot 22 is subject to theaction of elastic return means previously envisaged, the movement of thesaid pivot 22 in the housing 24 in a direction parallel to the axis ofthe sleeve 13. It will be the same for the lug 23 so that the valve 10,at the beginning of its opening, has a movement of translation until thepivot 22 comes into abutment against the portion of the housing 24spaced from the intake port 6.

From this moment, the pivot 22 no longer being displaced, the lug 23will describe, around the said pivot, in clockwise direction, an arc ofa circle. There results, for the valve 10, a tilting movement inclockwise direction around the axle of the lug 15, which axle has amovement of translation from right to left of FIG. 2.

In the course of opening, the valve 10 is oriented substantially alongthe axis of the intake pipe and does not 6 project by any of its partsinto the free working chamber 4.

The passage open to the flow of fresh gas coming from the carburettor ismaximal which is favorable for operation at full load.

As result of which, there is obtained an obturating device for theintake pipe which responds well to the desired purpose and which it hadbeen sought to attain, namely, reduction to a minimum value, when theclosing of the obturating device is complete, of the dead space in theintake pipe into which the burnt gases can penetrate.

In addition, as soon as the engine no longer opprates at full load, theobturating device ensures efficient throttling of the said intake pipe,by reason of the rapid tilting movement of the valve 10, limiting theentry of the burnt gases.

As is self-evident, and as emerges already from the foregoing, theinvention is in no way limited to those of its methods of application,nor to those of its methods of production of its various parts, whichhave been more especially indicated; it encompasses, on the contrary,all variations thereof.

I claim:

1. Obturating device for the intake pipe of an internal combustionengine, said engine being supplied with fuel through a supply devicecomprising means adapted to ensure suitable metering of air and of fuelunder all conditions of operation of said engine and being provided withat least one intake port and one exhaust port of which the opening andclosing are actuated by the piston of the engine, said intake andexhaust ports communicating with one another during a fraction of acycle, said obturating device comprising a valve actuated by a mechanismarranged so that said valve can be fully opened and oriented in adirection substantially parallel to the axis of the intake pipe at thelevel of the valve and can be oriented transversely to said axis toclose the intake pipe at a distance from the peripheral surface of thecombustion chamber of the engine less than one half of the dimensionalong the said axis of the valve when the latter is fully open, theassembly being such that the said valve cannot project into thecombustion chamber of the engine, whether it is open or closed or in anintermediate position, said actuating mechanism comprising a rod adaptedto slide in a sleeve, inclined on said axis towards the intake port, oneend of the said rod projecting into said intake pipe, the middle portionof the said valve being articulated on said one end, the other end ofthe rod being connected to a member actuating the longitudinal movementsof the said rod and a link member of which one end is articulated in apivot mounted in said sleeve and on the other end of which isarticulated the portion of the valve situated, when the latter is open,closest to the intake port.

1. Obturating device for the intake pipe of an internal combustionengine, said engine being supplied with fuel through a supply devicecomprising means adapted to ensure suitable metering of air and of fuelunder all conditions of operation of said engine and being provided withat least one intake port and one exhaust port of which the opening andclosing are actuated by the piston of the engine, said intake andexhaust ports communicating with one another during a fraction of acycle, said obturating device comprising a valve actuated by a mechanismarranged so that said valve can be fully opened and oriented in adirection substantially parallel to the axis of the intake pipe at thelevel of the valve and can be oriented transversely to said axis toclose the intake pipe at a distance from the peripheral surface of thecombustion chamber of the engine less than one half of the dimensionalong the said axis of the valve when the latter is fully open, theassembly being such that the said valve cannot project into thecombustion chamber of the engine, whether it is open or closed or in anintermediate position, said actuating mechanism comprising a rod adaptedto slide in a sleeve, inclined on said axis towarDs the intake port, oneend of the said rod projecting into said intake pipe, the middle portionof the said valve being articulated on said one end, the other end ofthe rod being connected to a member actuating the longitudinal movementsof the said rod and a link member of which one end is articulated in apivot mounted in said sleeve and on the other end of which isarticulated the portion of the valve situated, when the latter is open,closest to the intake port.